You're looking at the world's first manned flight powered by a hydrogen battery. Boeing's prop-driven aircraft set the lone pilot aloft for about 20 minutes at a speed of 100-kilometres (62 miles) an hour at an altitude of about 1,000 meters. The 800-kilogram (1,760-pound) craft with a 16.3-meter (51-foot) wingspan is capable of flying for about 45 minutes under the power of its hydrogen fuel cells -- the airplane's batteries provided an additional boost for takeoff. The fuel cells harvest the energy produced by the chemical transformation of hydrogen and oxygen into water -- that makes the craft clean as well as near silent. Unfortunately, the technology is nowhere near the point of powering commercial aircraft. At best, the fuel-cells could act as a secondary power source... in another 20 years.